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Get your free estimateWhy San Francisco Homeowners Choose Therma-Tru Windows & Doors
We provide Therma Tru in San Francisco, repairing and installing Classic-Craft, Smooth-Star, Fiber-Classic, and Pulse Series products across the city’s Victorian, Edwardian, and mid-century homes. What makes our Therma-Tru work different is that we see how these specific doors behave in this specific climate: salt air corroding multi-point lock hardware, marine-layer moisture working into bottom stiles, and settling foundations throwing door slabs out of alignment. Lightwell Windows San Francisco is not affiliated with or authorized by Therma-Tru. We’re an independent service provider, which means we fix what’s actually wrong rather than steering you toward a replacement because it’s easier for us. Call (831) 480-4124 for a written estimate before any work begins.
Why Trust Lightwell Windows San Francisco for Your Therma-Tru Windows & Doors?
Our field teams provide Therma Tru service in Castro Valley and weekly across San Francisco’s housing stock. That repetition matters because Therma-Tru products fail in predictable ways here, and we’ve learned exactly what those patterns look like. The fog that rolls through the Sunset District doesn’t just rust hardware. It works into fiberglass skins at the bottom stiles, and by the time a homeowner notices the delamination, the core has usually been wicking moisture for months. We know to check that seam first on a Classic-Craft door in the Richmond or the Sunset before we even touch the hinges.
Keith Yamada, owner at Lightwell Windows San Francisco, learned glazing systems and building construction at Los Angeles Trade-Technical College and spent weekends as a kid weatherstripping his family’s 1960s ranch house in the San Gabriel Valley. That early habit, checking every corner twice before calling a job done, still runs through how our whole crew approaches Therma-Tru service. We read the existing frame carefully before a single panel comes off the wall. We want to understand what the original installer got right and what the weather has undone since. That is the difference between a repair that holds and one that just buys you a year.
Styles & brands we work with










Common Therma-Tru Windows & Doors Problems We Fix in San Francisco
- Fiberglass skin delamination on Classic-Craft Mahogany Collection doors. Standing fog moisture seeps into the bottom rail seam, usually where the sweep meets the stile, and the fiberglass skin starts to separate from the core. It looks like bubbling or a soft ripple near the threshold. We repair this by drying the core, re-bonding the skin with marine-grade adhesive, and sealing the rail with a barrier that stands up to salt air better than the factory product.
- Warped or binding door slabs on Smooth-Star Fiberglass Entry Doors. West-facing exposures in neighborhoods like the Inner Sunset get direct afternoon sun for hours, and over years the Smooth-Star slab can develop a slight bow that makes it bind against the frame in summer. In winter the door usually behaves, which is why homeowners sometimes dismiss the problem. It’s the thermal cycling. We fix this by adjusting the frame, re-shimming where needed, and in some cases replacing hinges with a heavier-gauge adjustable set so the door hangs true through seasonal swings.
- Failed compression weatherstripping on Pulse Series Patio Doors. Hilltop homes in neighborhoods like Diamond Heights and Twin Peaks get real wind, and the factory compression strips on Pulse sliding doors compress over time and stop sealing. You’ll feel a draft at the meeting stile even when the door is fully closed. We replace the factory stripping with a marine-grade aftermarket seal that holds its shape longer in the wind and fog.
- Sticking or misaligned panels on multi-point locking systems. Older San Francisco foundations settle, and when they do, a Therma-Tru door with a multi-point lock starts fighting itself. The upper and lower lock points stop lining up with the strike plates, and the handle gets harder to throw. Forcing it makes the problem worse. We realign the slab, reposition the strike plates, and re-lubricate the lock body so the mechanism throws cleanly again.
- Rusted shut steel casement windows adjacent to Therma-Tru entry systems. In the Sunset and Richmond districts, 1930s-era stucco homes often have original steel casement windows that have corroded in the salty fog, and homeowners sometimes assume the whole opening needs a full replacement. Before we touch a Therma-Tru door in the same wall, we assess those windows. A retrofit is often possible, and it keeps the period look intact.
Therma-Tru Parts & Our Repair-vs-Replace Approach
We stock OEM Therma-Tru replacement parts locally for the components where factory parts genuinely matter: multi-point locksets, adjustable hinges, and strike plates. Those pieces have exact tolerances, and aftermarket substitutions almost always wear faster or throw off the lock alignment. For weatherstripping, sweeps, and patio door rollers, we recommend quality aftermarket options when they outlast the factory material. The marine-grade compression stripping we use on Pulse Series doors is a good example. It’s not what Therma-Tru ships, and it holds up better near the ocean.
Our default is repair rather than replacement whenever the fiberglass skin and core are still sound. That’s especially true for period-matched entry doors on historic Victorians and Edwardians. Replacing one of those means custom millwork to match the original trim, and that gets expensive fast. If we can save the slab and restore the seal, we will tell you that honestly. Call (831) 480-4124 for a written price before you decide.
Our Therma-Tru Service Process – Step by Step
- 1
Diagnosis. We inspect the full door or window assembly, not just the symptom. On a Classic-Craft entry door, that means checking the bottom stile seam for moisture, testing the multi-point lock points one by one, and running a smoke pencil along the weatherstripping to find the actual leak. You get a written diagnosis with photos and a line-item price before we touch anything.
- 2
Repair or install. We lay drop cloths before the door comes off its hinges. If we’re replacing an entry door, we protect the threshold, the surrounding floor, and any furniture within the swing radius. Our techs wear shoe covers on every visit. We ask before we move anything, and we explain the price for every step before the work happens.
- 3
Test. Once the repair or install is complete, we test the full assembly: lock points thrown and retracted ten times, a smoke-pencil draft test at the meeting stile and the threshold, and a check for any light gap around the perimeter. If it doesn’t pass, we stop and fix it. That’s the 365-Day Done Right Promise working retroactively, not as a marketing line but as the way we check our own work before we load the truck.
- 4
Clean-up and warranty. We photograph the doorway and floor after clean-up, then walk you through what we did and why. Every job gets the 365-Day Done Right Promise in writing: if the finished work is not right, we make it right. No countdown, no debate.
See the difference
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After
Before
After
Before
AfterTherma-Tru Products We Service & Install in San Francisco
We service and install Therma-Tru’s core product lines: the Classic-Craft Mahogany Collection, which is the fiberglass door most commonly found on San Francisco’s Victorians and Edwardians; the Smooth-Star Fiberglass Entry Door line; the Fiber-Classic Oak Collection for homes that want a wood-grain look without wood maintenance; and the Pulse Series Patio Doors, which appear on everything from Noe Valley flats to mid-century homes in the Sunset. We stock common OEM lock bodies, hinge sets, sweeps, and weatherstripping locally so most repairs don’t wait on a parts order. We also install new Therma-Tru entry doors and patio doors through our Window Replacement services, and we carry the flashing, sill pans, and sealants that make an install hold up in the fog and salt air.
We Also Service These Brands
We carry eight manufacturer brands, so a Therma-Tru question never corners us into a Therma-Tru answer. If a window or door from PGT, CGI, CWS, or ES Windows is the better fit for your specific opening and exposure, that’s what we’ll recommend. The right product depends on the home, not on what we happen to have in stock.
FAQs – Therma-Tru Windows & Doors Service in San Francisco
Yes, if the core hasn’t rotted through. Bottom-rail delamination on Classic-Craft doors is the most common Therma-Tru failure we see in San Francisco, usually caused by fog moisture sitting at the threshold seam. We dry the core, re-bond the skin with a marine-grade adhesive, and seal the rail so salt air doesn’t repeat the damage. If the core is structurally compromised, we’ll tell you honestly and give you a replacement price before you spend a dollar on repair.
That’s thermal cycling. A west-facing Smooth-Star slab in direct afternoon sun gets hot enough to bow a few millimeters, and that’s enough to make the door bind against the frame. In winter the slab cools, contracts, and swings free. The permanent fix is usually re-shimming the frame and switching to heavier-gauge adjustable hinges, not planing the slab. Call (831) 480-4124 for an in-person diagnosis and a written estimate.
Yes, routinely. The factory rollers on Pulse Series patio doors are decent but not exceptional, and in San Francisco they wear faster when salt air corrodes the bearings. We use a stainless-bearing aftermarket roller that handles the marine environment better and costs about the same as OEM. The door will slide noticeably easier after the swap.
Almost always, yes. We install Therma-Tru entry doors in Victorians and Edwardians throughout the city, and we treat the original trim as the priority. That means careful removal and re-installation of period millwork, custom shimming to match the existing rough opening, and flashing details that work with the home’s original construction rather than against it. We’ll tell you upfront if the trim is too fragile to survive the job, which happens occasionally, and what the alternatives are.
We realign the slab, reposition the strike plates, and service the lock body. In San Francisco, foundation settling from seismic activity is a regular cause of multi-point lock misalignment on Therma-Tru doors. Forcing the handle is the worst thing you can do. It bends internal linkage parts and turns a $300 alignment into an $800 lock replacement. If the lock body is already damaged, we use OEM Therma-Tru replacement hardware to keep the warranty intact.
Most Therma Tru in Danville and San Francisco repairs run between $180 and $550, depending on the work. A weatherstripping replacement on a Pulse patio door might run $180 to $280. A full multi-point lock realignment with new strike plates usually lands in the $350 to $550 range. New Therma-Tru entry door installations typically run between $2,800 and $6,500 per opening, depending on the door line, the condition of the existing rough opening, and whether we’re matching historic trim. Every job gets a written line-item price before any work starts. Call (831) 480-4124 for an exact quote. Estimates are free.
Book Your Therma-Tru Service in San Francisco, CA
Call (831) 480-4124 to schedule your free estimate. We’ll send a background-checked, uniformed technician to your home, put the price in writing before any work starts, and treat your floors, furniture, pets, and kids’ sleep schedules with the care they deserve. That’s the Cedarwell Care Promise on every single job.
Written by Keith Yamada, Owner at Lightwell Windows San Francisco, serving San Francisco since 2010.
Six Reasons Homeowners Choose Lightwell Windows San Francisco
Laminated glass and reinforced frames hold up to wind-driven rain, hail and flying debris, so your openings stay sealed when the weather turns.
Low-E insulated impact glass from our manufacturer lines commonly cuts monthly cooling bills 20-30%.
Laminated impact glass shuts out up to 40% of outside noise - traffic, neighbors, weather.
Monitoring services run $30-90 a month. Laminated impact glass resists forced entry around the clock, with no subscription.
Tighter seals and insulated glass even out hot and cold rooms and stop the drafts at the frame.
A full impact package upgrades curb appeal, buyer confidence and appraised value in one project.